Perspectqgraph



W. B. EMBRY.

PERSPBGTOGRAPH.

(No Model.)

No. 248,725. Patented Oct. 25,1881.

UNTTED STATES PATENT @maca c WILLIAM B. EMERY, OF ALBANY, NEV YORK.

PERSPECTQ'GRAPH.

SPECIFICATION forming part of Letters Patent No. 248,725, dated October 25, 1881.

Application filed February 9, 1881. (No model.)

To all-whom it may concern Be it known that l, WILLIAM B. EMERY, of the city and county ot' Albany, and State ot' New York, have invented certain new and useful Improvements in Perspectographs, ol' which the following is a specitication.

My invention relates to apparatus for drawing perspective views from natural and articial objects; and the object ot' my improvements is to provide a simple, cheap, and reliable device for mechanically transferring to a plane the perspective lines ot' objects without recourse to the usual complex manipulations required t'or linear perspective. This object I attain by means ot' the mechanism illustrated in the accompanying drawings, which formsa part ofthis specitcation, and in which- Figure l is a perspective view ot' my apparatus; Fig. 2, a side elevation ot' the saine, and Fig. 3 an end view of the collimating portion ot' the apparatus.

As represented in the drawings, A indicates the base-piece ot' the apparatus, attached to the head B of a standard (pert'erably made in the form of a tripod with adjustable legs) for supportingthe device while in use. Said basepiece is pivoted to the head B by the clampscrew b, in such manner thatiit (the bed-piece) can be adjusted at any required angle.

The movable standard O is provided at its lower end with a pintle, (shown by dotted lines in Figs. 1 and 2,) which enters a socket, a, erected for the purpose near the back end of the base-piece, and serves as vertical 'axis for the standard C and its attached parts.

A vertically-vibrating arm, D, is pivotally connected by the pin d to the upper endot' the standard C, and is provided with an eye-piece, E, fixed transversely to the arm D over its pivotal center, and in a perpendicular position to said arm. Said eye-piece is composed of a disk of metal or other suitable material7 having through its center a small sight-hole. At the outer end ot' the arm D is secured a short open cylinder, F, provided with two fine wires, j', which cross each other at right angles at the center line of said cylinder.

A lower vibrating arm, G, is pivoted by the pin g to the standard C, so as to range in line with the arm D. Both arms, D and G, are connected together bythe rod H in such manner that they will, in all changes of position, maintain a perfect parallelism between them. The arm G is provided with a marker or pencil, I, which is adapted to slide in the loops g', or other suitable appliance, to enable the marker to shitt inwardly or outwardly, as required by the varying positions of the arm G.

A slide, J, secured by the binding-screwj, is adjustablytixed to the base-piece A, and is provided with the drawing-board K. Said drawing-board is arranged at right angles across the center line of the base-piece A and in a perpendicular position thereto, and it is secured to the slide J by the thumb-screw k, so as to be readily detached.

Paper or other material upon which the drawing is to be made is tirstsecured to drawing-board K, and an advantageous point ot' sight in respect to the object to be drawn should be secured for the. position of the apparatus. Y

The mode of operating the device is as follows: The outer point of the marker I should be steadily held by the operator in perfect contact with the t'ace of the paper on the drawing-board K, so as to produce clean, distinct, and unwavering lines or marks on the paper. The eye ofthe operator must be constantly applied to the sight-hole iu the eye-piece E, and the line of collimation formed by the sighthole and cross wires j' should, through all changes of motion ot' the arm D, accurately follow along the outline ot' the object from which the drawing is made. The vertical axis ot' the standard C and the horizontal pivot d permit the outer end ofthe arm D to move in any required direction while following the outline, and any movement of the arm D, however complex in its nature such movement may be, will be simultaneously made by the arm G, and

may be traced by means of the marker I on IOO I claim as my invention- 1. A perspectograph composed ofthe following parts: a verticaIly-vibrating arm provided with collilnaring` attachments, consisting of an eye-piece and cross-Wires secured to opposite ends of and moving with said arm, as herein set forth, and an arm provided with a telescopically-sliding marker, as described, both of said arms being,71 pivotally connected to each other and to a central standard, to vibrate together vertically, and to swing laterally around the vertical axis of' the central standard, the Whole being arranged, as described, so that the perspective lines of an observed object may be mechanically7 transcribed thereby upon a plane surface, as herein speciiied.

2. In a perspectograph, the combination, with a central standard, C, having` its axis arranged in or near a vertical position, of the vertically-vibrating arms D and G, pivoted to the standard C, as herein described, and connected together by the rod H, to produce a simultaneous and corresponding movement of said arms, the arm D being provided with an eye-piece, E, and crosswiresf, and the arm G, adapted to receive a telescopically sliding marker I as herein specited.

3. The base-piece A, standard C, and vibrating, arm D, provided with collimating attachments, as herein described, and connected by the rod H to the arm Gr, adapted to contain a sliding, marker, in combination with a drawing-board, K, arranged in relation to the axis ot' the standard C as herein specified.

WM, B. EMERY.

Witnesses:

W ILLIAM H. Low, JOHN BURNS. 

